ORANGE GSM, How to keep a prepaid phone active for less than 7zł per month?

Orange fucked up, they changed something and I don't understand what to do if I want to spend NOTHING and only have active incoming calls and an active number. A few days ago, I recharged 5 PLN and now I have a total of 9 PLN, but now they are texting me that they will take away those 9 PLN because "To continue using the phone, recharge the account or extend the account's validity and accumulated bonus gigabytes by +31 days by replying AKT31 to this SMS (7 PLN + SMS in Orange). More at orange.pl" - yeah, I think less. I will not spend 7 PLN every month just to extend the number, are they crazy? (At this point, there should be a tag for Orange, so that ccfound sends them a message that someone has a problem with them and let them come respond) How to extend it, because I only recharge with 5 PLN from time to time, only when I want to make a call and then AKT1 and I have the whole day of calls for 1 PLN, but I want only incoming calls to be active and the number to be active, how to do it and not let these idiots from Orange take advantage of it, how to keep this prepaid phone active at the lowest cost?