cable card won't work

Last week my Tivo live TV (Comcast) went out. The signals are fine, they are just not getting to the Tivo. The tech at the cable card department tried to reset the cable card but in the end sent me a new card. Meanwhile I got live TV several times for several hours. 

The new card arrived and the tech did something and suddenly live TV was back!  Unfortunately I had not put the new card in.  So I did that and went through an hour of Tivo bootings until finally it was ready to be paired.  I called and got a new tech, who sent signals three times but none worked.  Interestingly, he said the card was getting paired but it looked like something else failed, which he said was common enough that customers were being sent several cards to increase their chances of getting a good one. So he is sending me two more cards. <sigh>. He did suggest that I take the card from our other Tivo, and since we know that it is working, and install it in the problem one, then call and see if it can be paired. IDK what that would accomplish except possibly kill our remaining good Tivo.

The trouble is, it takes a very  long time to get from the "Hello, this is Comcast," to the right department and then it is an hour giving the card info to the tech and watching the card install.  Then another very long time to get the right department again and a half hour while the new tech tries to get it working.   This to find out the card failed and... shall we try another? 

I have the feeling that some techs know what they are doing and many others are just following some script that does not work.  How can I get a smart one? I read here some folks got techs to come out to their house and install, how can I get one of those? The method I am using now is killing me!

[Edited: "Personal Information"]

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