faulty battery...OR Not working charging

Bought a battery for my garage door on the 13 September 2022, today 27 September 2022 took it back and I was told I should have bought a multimeter to test the battery... really? I was made to sign a repairs job card document which I did not understanded. May I please have my full refund to buy a battery elsewhere. My suspicious about the buying a battery from them rose when I was told not to return the battery after purchase. Fortunately I had my old battery which was tested and it read 24.4 Volts and their battery read 10 volts.