[OSM-newbies] Someone has corrupted my input

[Cliff Deamer]

Back in October/November I spent some time mapping a new residential
development and adding names to unmarked roads.
When I checked this morning I find that someone has changed my work,
adding or deleting roads and changing road names which are now
incorrect.
Does anyone else have similar experience? if so what can be done about
this?
Thanks  Cliff