HSBC credit card

SPWILL

hi I was banking with hsbc for around 5 years and had account and credit card. Around 2 years ago they closed my account without explanation. Apparently they don’t have to. Branch manager said he could understand why as no suspicious activity on my account.
i have a really great credit rating and can borrow large amounts no issue due to salary, credit score, LTV in property.
All very strange.
roll forward 2 years. I sign up for balance transfer for 34 months I think with around 3% transfer rate from hsbc. Only went for it as it was longest time.

So I get accepted, transfer amount and four weeks later I get letter of closure of credit card account. So I contact HSBC, again bullcrap about regularly reviewing account. So I say I’ll happily transfer amount £3700. But I’m not paying the balance transfer amount due to not being allowed the time to pay balance. They say they can’t remove charge as the balance transfer technically went through. The account closure date is 3/12/25. Where do I stand. I asked to speak to customer service to complain and was told they were customer service. So I’m considering visiting branch. The interest amount is under £200. But I don’t want to pay money out of principle. Why accept me then? Why give me card and offer to remove it four weeks later? Pls advise. 

Regards