Granted, the "nickel and diming" of hotline numbers (1900, 0900, etc) was nowhere as bad as today's cash shops, but a lot of us simply forgot they were always hungry for all our money
Here's a bunch other hotline ads for you to peruse - https://www.retromags.com/gallery/category/1729-telephone-hotlines/
PS: I never understood these american numbers that used letters, how were you supposed to know what was the actual number?
You just press the number that has the letter, regardless of if the letter was in the beginning or the end, you just press the number wherever that letter is.
Fun fact, it's a carryover from when dial service was first implemented in the United States!
In the beginning, you'd pick up the phone and hear "Number please?" and then you'd tell the operator the central office name followed by the number, like "Bubbling Brook 3-2468" or "Murray Hill 5-9975"
Once dial service was implemented, you'd instead hear the dial tone and then dial the first two letters of the office name, followed by the rest of the number (BU32468 or MU59975), using this arrangement of letters.
Once phone numbers went to all-digits around 1961, the letters on the dial got repurposed for numbers like these. Of course, they got repurposed again for T9 texting and contact search.
AT&T has an old video about this topic
and the "DRM" of the day was typing in the third word of the second paragraph on page 6 of the printed booklet that came with the game.
Some games let you keep playing without the correct code... until the difficulty automatically ramped up to impossible levels.