Product: Checking or savings account

When we opened a CD account at Wells Fargo Bank XXXX. We were promised an amount upon maturity which we did not receive. 
The banker XXXX XXXX and the branch Manager both explained to us in XX/XX/XXXX that we would receive 35 % at the end of 6 years XXXX Here is the branch managers direct statement : The account is set up to where there would be no interest to very low interest payed to this account during the first 3 years, the very last 3 years mostly last year is when you will start to see the funds applied to the account. Because of the way this calculation works- in the percentage block you see 0.35 % instead of 35 % which is what you will receive if the account stays untouched full 6 years. So at the end you will receive over {$12000.00} which will include the amount invested. The calculation used for CD account is XXXX ( the original amount ) x XXXX = XXXX and time by 6 = XXXX interest. We made sure that the Manager of the branch entered this information including the ammount promised into the notes and she did so directly in front of us so that we continue with account opening. 
We called every year and each and every individual we spoke with, confirmed the end result of this account being 35 % One of the representatives we spoke over the phone with stated that our account was closed and reopened and then after we did not agree with this statement he placed us on hold and came back to say that everything was as it should be which could be the time the bank tampered with original set up of the CD account we opened. 
Each time we spoke with them - bank confirmed the amount which we would receive which was over {$12000.00} But when we came to close the account- they closed an account with .35 % clear calculation.XXXX.35 % XXXX x6 years=XXXX which is not what was said when we opened an account. 
As we filed the complaint with the bank- the resolution was that they will issue {$500.00} check for client appreciation and they will close out account and remove all the bankers notes with the help of XXXX. The website provided is temporarily unavailable at all times and no one is answering the calls. The time they provided for everything to be removed from record is 4 weeks and when we go to the branch- the clerk stated that the notes are in the system indeed, showed us the notes and we are working on printing those for the records. The amount promised at the end of 6 years was {$8300.00} difference between what was delivered. 
We would like to review all notes from each call we made and all notes which banker and branch Manager entered so that this bank understands that it is not ok to do this. This is unfair and deceptive practice and our daughter is paying {$8000.00} from her collage to this bank as end result. 
The lady which called us about the investigation also saw the notes and attempted to name the ammount promised an estimate provided by the branch manager, not the actual ammount How can a manager tell us we would receive {$8400.00} and we receive under {$84.00} instead? 
The manager of the bank was very sure in her statement and she convinced 3 of us who came to the bank that day that she is saying the truth and stated that if we do not get the amount she promised - her notes will secure the CD because she swore the information is correct which the bank provides!