ADSL to VDSL upgrade nightmare

Requested upgrade from ADSL line to 40MB VDSL on 2 February 2015 specifically staying on month to month billing. To date since request lost all connectivity (both DSL line and ISP). Latest bill indicates advanced billing for ADSL line, as well as DOUBLE billing for 24 month VDSL contract opened without my permission ??? Despite dispute logged with Billing as well as fault escalation number received from Tecnical support, NOTHING has been done. Still no internet and told that I must pay as per incorrect invoice ?? I want to do business with Telkom, but it seems impossible. Please help !!!!