。
Thank you very much.
Literal
Rarely-[be-there-て]-exist-[polite-ございました].
ありがとうございました is the past tense of ありがとうございます — 'thank you very much [for what you did].' The etymology is telling: ありがたい ('rare, hard to come by') becomes ありがとう in its old adverbial form, joined with the humble ございます ('to exist'). Literally 'it was a rare/precious thing.' The kanji 有難う ('exist-difficult') exposes this origin.