Battery problem, don’t know what to do?

Hello together, If I ended up in the wrong department, just move, thank you. The following problem, I bought a battery in December 2016, battery until September 2017 everything went well. October 2017 I had to apply 4 x starting aid because the battery was down, because I picked up the battery myself in the shop and still had warranty, I had them tested in November, that alone took 5 days no idea why the so long brew where I could then pick them up again I was told that the battery was reanimated again and was so far ok. So again built in, at the end of February the started again battery went down again 2x starting aid requested was down to 11,5 volts, the ADAC Man who helped me dan said that the charge was ok with 14,3 volts fluctuated but up to 14,0 volts, I drove around over an hour to charge them full. A day later looked again and measured the battery, showed only 11,8 volts the ka nn don’t be, or. I then measured creep current. in sleep mode 0.02 Ah with door opening 0.25 Ah and then I turned on the ignition 1.68 Ah But the numbers are ok that way, right? What do you think the battery defect is