Nonsensical debt collection sms.

My 87yr old dad suffered a major stroke in Feb 2019 and was hospitalized at Fourways life. He has the med aid which understandably has paid the majority of the bill. Since June 2019 I have been receiving this vague sms as a guarantor from Blake & assosciates representing Fourwaus life, saying that he owes Fourways Life... no amount or other information is supp****... I have called the Blake offices several times and the response I get is before they tell me how much is owed i must get a drs letter confirming that my dad is incapable of personally making the payment. As a guarantor why cant they give me the information so i can settle the account. Why should i incur expenses of calling in a dr (as he is bedridden) to come write a letter confirming he cant handle his financial affairs lastly why do you continue sending me the sms if I am not expected to resolve the issue. This is so nonsensical to me as all other companies give enough info so one can make payments.