WRONG prescription!!

I got my prescription glasses from your Tyger Valley branch just over a year ago. This was the first time that I have gotten prescription glasses. Within the few days I felt like my new glasses were not working for me. I called the shop and they said that this is normal as they are new and that my eyes would take some time to get used to the new glasses. I left it then as it was my first time getting glasses, i did not know better. Within the next few months I again called the shop and said that when I drive I still was having trouble seeing and that I really felt like something was wrong. They called me back into the shop and said that they would do another eye test. When i did re-do the eye test they assured me that my prescription was correct. I have just gone to a different optometrist and he told me the prescription i need vs what i was given from you is day and night. The optometrist did not understand HOW spec savers got it SO wrong. I showed him what I was prescribed. I knew something was wrong yet spec savers basically told me I was delusional and over and over dismissed that I was telling them these glasses were wrong. I paid 6k for a pair of glasses that i can basically throw away. I now have to again within 1 YEAR get new glasses as the one's prescribed to me are useless. I should be refunded!