Wrongful accusation

Beginning of January I took my car in to get grounded and was charged 11G as balance for what I owned on my vechile for the last couple of months Merceden lawyers have been calling me accusing me of owning 62000 only for me to take this matter into my hand and get a hold of their legal department I sent them my contract and emails to prove that I don’t owe that amount a guy named miro from head office apparently didn’t update my contract hence the 65000 owing they have just gotten back to now saying the actual amount was 17G no apology nothing this has affected my health and given me sleepless night. I thought this was an international company with international standard I guess not ?????????????????????????