I received my new credit card in April of last year, but I was unable to use it because Tesco blocked it immediately after the first use. I called customer service several times, most recently two weeks ago, and was told that after 45 minutes on the phone, they would call back to sort it out and remove the flag from my card. I even received my new card with my pin, but I never received a call back, and neither of my cards worked. I just don't understand why, as far as I recall, I never missed a single payment and my balance was always zero. Please respond and resolve this issue, either by unblocking my card or closing my account.