I'm disappointed 😥

I bought double sided tape 2 days back when I put it on my mirror if fell off and broke😭 I asked the guy that helped me will it work on my mirror then he said yes and we never spoke about how big is the mirror he just said I have this that you can use on your mirror it's expensive though! Then I said the price says it's worth buying and I bought it with 2 other item. I went there this morning to ask for refund or give me something that works ill pay for the extra unfortunately I had no slip but I paid with my card 💳 the manager said I must pay double the amount to get get refund which is madness I left it the the double sided tape they can have it