Mytrip.com complaint: Cancellation of the flight to Germany

I have bought return tickets from Frankfurt to London
My partner traveled earlier before lockdown and my flight has been cancelled just the date of my travel

I called to cancel my return tickets unfortunately my ticket from Lufthansa is not refundable they have offered me to change the date of my tickets this progress took 5 hour’s in total on the phone

I have called to change my flight they asked me pay £120 extra to change my flight to April the 11th, when I checked the date of tickets on Skyscanner the price i get was only £49 and i did not expect and wanted to talk to a manager

The manager or supervisor did offer me to look at it for me and asked for a 30£ difference and i have paid the amount and change the date of my flight

I did not receive any ation from then and i had to call next day And they have checked and told me that both of the tickets was changed to 11th of April and an other 3 hour’s on the phone and ne response from the supervisor still waiting for a call

Unfortunately its been the worst experience ever