TSB debit card crisis

So i have a TSB debit card and wanted to buy an item online. unfrotunately it had been declined. so i tried to buy ir from a different website. same issue arose.
i know that i have the adequate amount f funds as i checked yesterday and i know my PIN is correct for that matter.
months ago the same issue happened as i wanted to pay for an item with my card. but for some odd reason i was able to buy myself a kfc bucket. similar time ago i was able to withdraw £150 but as of now i can only do £50

Call them they should be able to explain why the payment was blocked, sometimes it's a simple as a technical problem.