MBD harassing me

I'm so irritated by the harassing phone calls, emails and SMS' from MBD. I have told them several times that my account with Edgars was fully paid in June at the store and I don't have the receipt, but they keep calling me. I explained that I'm not going back to the store and exposing myself to covid when they or Edgar's should liaise with each other. Im an Edgar's customer not MBD's. I've made my payment. They should get the proof of payment from their customer. When I call Edgars they confirm that the payment is reflecting and that my account is still active. They also said they don't understand why MBD is calling me because if the account is referred to them it should be inactive.