Customer no changed in dynamic nav to another number suddenly

I have dynamic nav 2009 r2 in customer card i have customer no 3099 changed to 3064 automatically without any changed

i dont have data port

Are there are any function or option changed this from number to another number

more explain

Customer No 3099(before 1 day)

(mention sample)

JE-PSI-000115 22/04/2014 22000

JE-PSI-000120 25/05/2014 2000

JE-PSI-000121 30/06/2014 4000

balance in card 2,000,000

Customer No 3064(After 1 day)

JE-PSI-000115 22/04/2014 22000

JE-PSI-000120 25/05/2014 2000

JE-PSI-000121 30/06/2014 4000

balance in card 2,000,000

What is the proplem and why it changed automatically

may be there are reason but i dont know what is reason

i ask here to know what possibility that make error to avoid this proplem after this

And i dont have developer license and Manually cannot changed from card because it has more transactions in

table customer ledger entry

In standard NAV, a Customer does not change identification in any automatic way.

Someone has changed that customer using standard-rename. Manually. That’s my statement.

Standard-rename does not demand a developer’s license.
Whether the customer has transactions or not - that’s not an issue in a rename-operation.