hello vinay here we have to see application of 2 clauses.
1st here firm has given money to client so client is indebted to firm, firm is not indebted to company hence not disqualified.
2nd can we call it business relationship, as ca firm is using banking services from client and it is not covered in exempted industries of hotel hospital airlines and tele communication hence firm will be disqualified. firm should move account to another bank before appointment.