I wouldn't accept that from customer services. You need to escalate your complaint, so ask them for their compalints procedure which they have to give you. Then put your complaint in writing & point out that under Ofcom's code of practise for sales & marketing of subsciptions to mobile networks, they are required to monitor the activities of such companies as phones 2u direct & make sure that they comply with this code of practise detailed on the following link:

http://www.ofcom.org.uk/telecoms/ioi/mbp/cop.pdf.

Hope this helps anyone trying to obtain mobile phone cashback