Vet overchanging

My feral cat was very ill on Sunday on the 26 of July 2020 we tried local vets they were closed we did not have transport as our car was in an accident and my husband and i are pensioners with high risk illnesses so we decided to hire a car when my husband got there the demanded 6000.00 as a deposit , my husband only had 2000.00 he then told to treat the cat as they said the cat might not make it so he said he will get the 4000 by Friday the 31st and left .the next day they called and said they will put him to sleep at 3pm as my husband asked them to cap the amount at 6000.00.They then called and said the cat is doing much better but rhey cannot do bloods or xray as 6000.00 is to little they put him on a drip and catheter to remove the urine .on tuesday he was doing much better and i asked if i can pick him up they said he is still a bit weak they will call on Wednesday. so they called with a bill of 7434.10 and we then told them we can afford the 6000.00 as agreed, they insisted we pay and send proof of payment before we colect him we paid and mailed and asked if we could pick him up as we hired the car and they then said we must come at 3pm we lost the money we paid to the car hire and now they say they will inform us the he dif not urinate which was at 2pm and we paiid at 10am.So which means the bill is running up which i cannot afford. i asked for a detail invoice which i did not get just the amount .i always thought that vets had emphaty ,during this trying times people are giving pets to shelters and here i am that feeds feral cats from the neighbourhood and we get scavengers like this Clinic . I pray they will release my cat as they have received their money .they knew we capped the amount or told me the next morning to go to the SPcA .this is why people abandon pets .

kind regards Vanita