Does anyone at Yoco know how to reply to a mail unrelated to sales?

I am terribly saddened by the utter lack of customer service the last month from Yoco. I have given my Yoco to my mom as I am not using it and she desperately needs it and have sent in the transfer documents but I have had zero replies or correspondence from them despite daily mails asking how to change the bank details to my moms bank account as I am now getting all her payment through my account. I did not even get acknowledgement of the receipt of my documents. Trying to contact them through social media portals is also a lost cause.