Credit on Sub Account

I had this problem exactly a year ago. I have a parent account where all three subaccounts roll up into it. On the main account it says I have a payment past due and it's because Comcast randomly has decided to put a payment on the subaccount, giving the subaccount a credit. When this happened last year, it took about 4 months to finally get it fixed. I have no idea what triggered it this year. Anyone else have this happen to them? I don't feel like being on the phone for hours again multiple days a week for months for it to finally get fixed and stay fixed.