Sick and Tired of the Incompetence

i Joined Virgin Active 2017 but never used the membership due to unforeseen circumstances long story short i received a call that i must the pay the membership, a consultant sent an sms on the 13 November, with a banking details from Standard bank account number :61010***6 branch code 05-10-01, i then paid R1300.00 on the 04/12/2018, so I've been getting calls from MBD and i keep on telling them that i paid up the account, i even spoke to the team leader Lebo on ********** 378, i told her EVERYTHING and while i was busy talking to her she said she's going to hang up the call if i don't want to listen to her, she said i must send a proof of payment, i advised that they must check the standard bank account and i gave her the ref and the amount of R1300.00 and she said a lot of people pay that round figured amount and she hanged up the call, i have a call recording for that day 07/01/2019, my problem is i'm still getting calls even today ( ********** 585, ********** 066 , ********** 977, ********** 942 etc ) i get calls from MBD EVERY DAY!!!!! i'm failing to understand why is no one checking the account or even communicating with Virgin Active regarding the amount i transferred, why is there no one checking that Standard bank account that they have given me to make payments to, i REFUSE to s**** feed MBD in sending them a proof of payment, i have to spend more money in sending that proof of payment, i'm even getting messages stating that i'm owing R1231.22 from ( ********** 297, ********** 865 ), i'm sick and tired of the calls and messages.