Product: Credit card or prepaid card

Account was closed. I had this account opened a long time ago and purposely kept it in good standing. I kept this card in good standing all these years. And it really helped my credit score. At the beginning of XX/XX/XXXX I began looking at my credit report. I was trying to bring up my score so that I could buy a house. I was going to request a credit increase on this card. I could not find the card to do this request online so I called XXXX. 
There is an automated recording. I put in my social security # and it asked me to identify which card I was calling about ( I have another card with them ) I put in the option for card ending in # XXXX which represents the account I opened in XX/XX/XXXX. The automated message told me that a new card was being sent to my house. I was very excited and was waiting for the new card. When I did not receive it I checked online to make sure my address was correct, which it was. ( I had changed apartments in the same building about 4 years ago and wanted to be sure it had been updated ) I did not receive the card. 
Well I just checked my credit score yesterday and they closed this account only two weeks after I got the confirmation they were sending me a new card!!!! It dumped my credit score 100 points! This is my longest running and kept in good standing card! If they were going to close my account they should have notified me and not told me they were sending me a new card! I would have used the account had I known this was an issue! 
I was on the phone all morning regarding this account! I was disconnected 8 times and had to start over, each person telling me they could not help me and that the closure was permanent! Finally one nice lady helped me and told me she would put in a request to re- open the account. I am terrified it wont work! 
Please help!!!!! 
They should not be able to close my account without trying to notify me of their intent. They stated they closed it because of " lack of use '' which was true, I did not use it. If I had been warned I would have used it. In fact I intended to use it which was why I was requesting a replacement card. I was also going to ask for a credit increase which I should have qualified for. 
Please help me! their decision to close this account despite telling me they were sending me a replacement card has ruined my chances of buying a house this year. It will take me years to rebuild the 100 points that were dropped from my credit score in their one callous action! I am terribly distraught and sad and horribly ruined by this credit card companies actions. Please reopen this account and send me the replacement card as they said they would at the beginning of XX/XX/XXXX. 
PS. 
If I call the XXXX number today. If I put in the account number for this account today, The automated message still says my new card is on its way and asks me if I want to activate the card they mailed to me!!! 


Please help!! I am desperate to reinstate this account to its previous 7 year of on time payment glory. 
Capital one card XXXX $ max balance opened XX/XX/XXXX/ closed XX/XX/XXXX Account was in good standing for all these years until it was closed unexpectedly.