Ensure EE tell you what your final actual contract monthly bill will be in £'s.
After four months my bill went up for CPI by a percentage and in 12 months time EE can not tell me what my monthly bill will be just that it will go up by a percentage set by the CPI.
It is corrupt and unethical for a company to enter a customer into an agreement, in which they can not tell the customer what the last month's contracted £ cost will be.