So in short, as I understood things, pre 01/01/21 if you bought goods from India you had to pay import VAT before you could have your goods, you then got a C79 and recovered the VAT (subject to partial exemption).
After that, you no longer need to pay the import VAT and for India read 'anywhere but the UK'. So if a client buys a widget from France they would receive the item and would record the VAT due and reclaimed on the VAT return the import occurs in. I'm led to believe this is the default position (though you can apparently opt to physically pay the import VAT if you want to!), but a client has experienced otherwise. They have been charged import VAT by a delivery company and were not given the option to do otherwise (and the delivery company felt they had done the correct thing by charging the import VAT).
Am I misunderstanding something or is the delivery company wrong? I've advised clients to expect not to have to pay over import VAT, and none have come back to say that hadn't happened.