Вот, Kote, как более близкий к истокам, подправил чутка:
Dear Madam / Sir,
I'm writing to you concerning the cycling computer which I bought. It's wireless O-synce mini freе and I have some problems using it. Time to time it shows completely wrong data (unbelievable speed 121,7 or 122,8 km/h) regardless of the cycle being in motion. I tried to reboot the computer, but it didn't help.
Could you answer, if this is covered by warranty or not, and how can I solve my problem?
Because I really like my computer and I want to use it further, but if such problem persists, I going to stop using it.
Sincerely yours,
Olga.
Мимолётное виденье нашего времени - велосипедистка с глубоким декольте.