overbill
/ˌəʊvəˈbɪl/verb
1 [with object] To publicize excessively or extravagantly. rare.
2 [with object] To make out or send a bill or invoice for (something) with a charge in excess of that which is due, especially with the intention to defraud; to overcharge (a person).
Origin
Late 19th century; earliest use found in The Century Illustrated Monthly Magazine. From over- + bill.