Product: Credit reporting or other personal consumer reports

XX/XX/XXXX : Changed car insurance to reflect 5 day a week commute starting XXXX XXXX. I had one month left on my old policy that should have been cancelled and supersceeded with new policy with the same company, XXXX. 
XXXX : Collections agency XXXX XXXX XXXX called to say I had {$100.00} outstanding on my insurance bill. I responded that it was an old policy and replaced with a new one, as my car can not be insured twice. I also was alerted to a dispute on my credit report via XXXX XXXX, and immediately disputed it and referred to the credit agency discussion. I hear no more and the adverse mark goes away. 
XXXX : I apply for mortgage with my bank and get excellent credit and offers - no evidence of a collection. I set a closing date on a house in XXXX. I start shopping around knowing for mortgages as I have a limited timeframe to have hard inquiries, and use this credit score from my bank to get estimates. 
XXXX : I select a lender and they check my credit. My credit score has plummeted XXXX points and my mortgage offers are rescinded and replaced with very expensive alternatives. My chosen broker shares my report with me and I see a collection for {$100.00}. All other aspects of my report are still excellent as shown in the reports run XXXX. I dispute it online at XXXX, Transunion and XXXX requesting it to be removed again on XXXX, XXXX. I call the insurance company and they say there is nothing outstanding on my account so I call the collection agency. They confirm it was removed in XXXX. I ask for a copy of the letter as they tell me it went to my old address from 2 years ago. I'm told they'll update the bureaus as a matter of urgency. I call the next day and nothing has been done. 
XXXX : I call each bureau and they tell me it can take 30 days to investigate but they can expedite if the collections agency sends them confirmation stating that the collection should be removed. 
I call the collection agency a third time and they have no record of my original call, and say they can't do anything to help. I ask for a copy of the letter again as it's been 2 days and no email, and tell me they can take 2 days to reissue and also send an email version. On XXXX I received the email version of the letter instructing the credit bureaus to delete the account. 
By now, my mortgage broker has told me that my only option is an FHA loan which has very expensive upfront fees and carries extra insurance payments for 11 years which is an extra {$15000.00} in total. 
XX/XX/XXXX : I asked my broker to check if a new loan was available, as I had confirmation that there was a change to my credit report and my score had increased with XXXX and XXXX following the letter from collection agency. 
I called both bureaus to ensure and they said that the account was no longer showing, although I couldn't see my new credit report as it was only available every 30 days, and I had run mine on XX/XX/XXXX. Transunion was unable to confirm the letter was received and unable to verify anything that could help. I tried to purchase my credit score and was unable to ( shown in screenshot below ). Given that this is a time sensitive issue and it had been removed once from my credit report, it's cost me {$15000.00} on an FHA loan for a {$100.00} invoice error.

My mortgage broker informed me that my credit score could be worse if I ask him to rerun it again as they are hard inquiries and I must pay the FHA fees.