IT has been tough going on the high street for some time now, but last week was particularly brutal. First the once mighty Debenhams announced it was shutting up shop, then Arcadia went into administration followed by Bonmarche. Where, and with which store, will it end?

TV has grown used to monitoring the health of the high street, and its demise has long been predicted in factual series and in news bulletins to the point where it seems inevitable. Inside Poundland: Secrets from the Shop Floor (Channel 4, Monday, 9pm) begs to differ.

Far from retrenching, the shop known for its cheap and cheerful wares is opening new stores to add to the 800-plus it already has, and it is investing £25 million in what it calls “Project Diamond”.

No, Poundland is not going into the engagement ring market, well not yet anyway. It is trying to go upmarket and bring in the middle classes. If Lidl and Aldi can do it, why not plucky little Poundland is the thinking.

This new two part series follows the management team and staff as they try to make the retail magic happen.

In the Walsall store, managing director Barry Williams has arrived to give the team a hand to stock the freezer cabinets with the kind of grub meant to be catnip to the middle classes. Chargrilled vegetable and pesto pizza followed by maple and walnut ice cream for dessert anyone?

Williams, who started off as a stockroom assistant at Kwik Save 30 years ago, can spot a profit margin a mile off and is big into positivity. As is his deputy, Austin, who is leading a team to Scotland. You may want to sprint for the kettle when the lads try out their Scottish accents for size. They definitely bought those at a discount retailers.

On arriving at the Glenrothes store, all is not well. The place is dusty, the shelves are badly stacked and the stockroom is the stuff of Mary Portas’s nightmares. The manager is given some friendly advice on how to fix matters and, just as importantly, a return visit is promised.

There are no hard feelings, as we see when the manager hands over some Poundland biscuits for the trip home to England. Never let it be said that in Scotland we let a guest hit the road without a cheap snack that bears a passing resemblance to a well known brand.

We next drop in on the complaints department, where they must be old hands by now at explaining it has been four years since the shop ended its policy of only selling things for £1. And we watch as the homewares department leads the charge upmarket with giraffe ornaments, photo frames and fancy planters. Taking on the likes of Ikea: now that is brave.

Will it work? If it doesn’t it won’t be through lack of trying.

Now, if you were in the market for a kick-ass foreign detective of the female persuasion, where would you shop?

Many might call in at The Bridge, home to Sweden’s Saga Noren (Sofia Helin), and that would be a good choice. But for some of us, Laure Berthaud (Caroline Proust) of the Paris police department will forever be our Selfridges.

There are some similarities between the two ‘tecs. Saga likes leather trews, Laure grubby denim. They are both highly intelligent detectives with razor sharp instincts. And they are both, it has to be said, disasters outside of work. Total emotional train wrecks. The only difference in Laure’s case is that she is not the most out of control maverick in her squad. Have you met Gilou?

I would highly recommend making his acquaintance when the BBC starts running the first series again in advance of the eighth, and final, season coming this way in January (iPlayer, from Saturday). It’s a lot to catch up on, but it is worth it.

Spiral is set on the Paris streets the train races past on the way in from the airport. This is definitely not the French capital as depicted in Emily in Paris. Berthaud and her squad are to Paris what The Sweeney was to London and Taggart was to Glesga. Down those mean streets someone must go, and they had better be rougher and tougher than the bad guys they are after.

Usually I can’t be doing with programmes that try to explain the magic of a comedy. Nothing kills the fun faster. But certain shows can take anything thrown at them, so you should be fine to watch We Love Dad’s Army (Channel 5, Sunday, 9pm).

Jimmy Perry and David Croft’s sitcom is the show that never grows old. No matter how many times you have seen it down the years it still rings fresh and true to human nature. That exquisitely timed comedy, those characters, every one of them well-rounded and recognisable.

Dad’s Army has become an old reliable, a refuge that is always there no matter how many other brash new comedies come and go. On the high street that is television may it never close its doors.