Lifetime is never the lifetime of a person. It's the lifetime of the account (limited by the lifetime of the company).
If a company gives me "free X for life", I can't expect X if they declare bankruptcy. If they get acquired, the acquiring company will probably be within their rights to cancel my free X, and this has been done time and again. You can try to die on the hill of "lifetime means my lifetime" but I don't know what you expect to gain.
Thus it's meaningless. Put "lifetime" or "unlimited" into a pricing plan and the one thing I know is that neither I nor the vendor can think rationally and honestly about it at all.
Thus it is a reason to look for another vendor who shows signs of realistic planning. If I can pay $50 for something that costs them $25 and it is obvious that it is roughly like that, I know I am partnering with a 'sustainable' business.
Seems like pretty realistic and sustainable planning to me, they give you at most 50 cents of credit to see if it works for you without a forced time limit.
You might have a point with general lifetime pricing plans, but in this case, I think the usage above of "lifetime free credits" was perfectly clear to most (and is in fact, limited).
I'll still be able to use this service in 2075?
Do you expect anyone to believe that?