Was charged for service i never received

I was asked to switch to xfinity mobile for less price, they never switched my services but started charging me ever month. I realized I was being charged from two companies for mobile service,  when I contacted xfinity I was told they never connected my line.  I was told I would get a refund by two employees,  but I never was . Now a supervisor told me that once the order was placed i got  charged whether it went though or not sure to policy they can't refund me $407