Impossible to cancel services at MWEB

I want to cancel certain items (services) on my monthly bill from MWEB. However, (Telephonically and on email MWEB has confirmed that my email address is blocked at MWEB, not sure why - we are in the media industry, in competition with a sister company of MWEB). The only email address I can get through to is, ***, not sure if it runs on a different email server. Webhosting refuses to give the message/ forward the email to billing.... I can try and cancel it online, but I first have to register a secure cell/pin for which I have to complete paperwork.... and email it to them... however, they make it impossible for me to email them.... If I phone them on ***, I wait the usual 15minutes plus, after which.... they cannot hear me and put the phone down in my ear. My account number is 920216, the services I want to cancel is - ***7; ***6; ***4; ***4; ***1.