Deceived to spend on what l dont have and not fulfilling what they said

My child was going schooling there for 4 yrs,and in 2023 which is last yr,l torch her out due to financial problems.l was owing them 2000,which it ended up being 5500 due to lawyers being involved.so we made arrangements on how to pay monthly,which l didn't have a problem with.my problem is last week they sent me a massage and called me as well, saying they have a discount for me,and l asked the amount to pay and they said 1500,that l should pay for them to close the account.and they said this offer was valid until 6 december.l did pay the money, actually l borrowed the money since l am not working but doing peace job.my problem is after the payment when l sent them proof of payment which is what they said l must do.now they are telling me a different story when l ask them to give me the proof that my account is close.they deceived me to pay the amount that l didn't have while l was ok with the arrangements