Yay the guys in India can now dick about with your account....
All intensely suspicious to me, I really can't see why 'tech support' would be doing this, it's really none of their business to upsell you anything, or to give anything for free, they are there to provide support and until they can actually get that right I'd question why they are pimping new products...
Unless this is the new way for ntl tech support of course, forget the support just give the discounts
Either way absolutely bizarre. I don't phone my ISP's technical support for them to offer me stuff for 'free' I phone them to resolve issues. There's a sales line for sales.