Your Purchase Could Not Be Completed

I want to share an interesting fact and a lie from Apple support staff.

I play a few games on my iPhone and sometimes make in-game purchases. I wanted to make a purchase in the Lineage2M game for $8.99, but I got this error:

Your Purchase Could Not Be Completed For assistance, contact iTunes Support at www.apple.com/support/itunes/ww/.

I didn't know what to do and forgot about this problem. A few hours later I wanted to make a purchase in FrozenCity app for $109.99 and it was successful. I thought that the error had passed and immediately tried to make a purchase again in Lineage2M for $8.99, but immediately got the same error.

I was at a loss. The next day I tried again to make a purchase for $8.99, but again I got an error. For the sake of experiment, I tried to make a purchase in Call of Duty Mobile for $109.99 and it was successful. After that, I tried to make a purchase for $79.99 in Lineage2M, but I got the same error again.

Can someone explain to me - what the **** is going on there? Why do I get an error in the Lineage2M game for buying $8.99, but in other games it can be done for $109.99???