That likely wasn't Ma Bells fault as such. I was in Europe in the late 1970's in Spain and Italy. When we hit port I would have to go to the phone company and sit sometimes up to 6 hours waiting on a phone line back to the states. The fade out or not being able to hear was because satellite technology was not an absolute science at that time. Your call either went via satellite links or by the trans-Atlantic cable. IOW the call was also as good as the other countries phone system which most of the time was U.S. hand me downs of our previous systems.
As a former AT&T Mgr. satellites were not used in 1970 for anything but experimentation..Overseas call were a combination of AT&T to the Trans-ocean cable or to High {4.0 MHz to 18.0 MHz range}Freq AM radio. Once you connected to the other country's technology, you became a victim of their equipment which was not 100% compatible with ours. Plus many of these countries were in the "dark ages" as far as telephone equipment. Fading was probably caused by use of the HF radio connection.
The call was from Kentucky to Florida. No transatlantic. Probably microwave. Still, indicative of poor customer service of a monopoly.