I cannot cancel an completed payment and cannot contact the company directly

[Alverio]

Hi i purchased an product an aggreed to withdrawl the purchase from my bank account, now i tried to cancel the order but i could not find that anyware in the app aswell as online but now i dont know what to do.. The company itself UK based is non reacheable by phone

[Alverio]

It also seems that paypal customer service is no longer available tried to call tried to chat but have not got any reply...