Yes,
Same scenario, escalate to 2nd level but the guy also don't know what is ms pptp vpn.sigh...
Ask them to open tcp port 1723 and allow gre ip protocol 47 also don't know how to do it.
I changed to maxis last week, it took 2days support and done.now can access vpn to office without problem.
As far as I concern, mcmc instruct telcos to block vpn access.
Only allow them by request.
Summore, after access granted, you need to change your apn and username password