アパートをレントしていてそこを売却にため2ヶ月後に退去するよう手紙が来ました。
こういった場合今月このアパートを出る場合すでに支払った今月の家賃が返金されると聞いたのですがどうなんでしょうか。
ご存知の方教えてください。
よろしくお願いします。

You'll want to have a look at section 50, which sets out how the tenant can handle a section 49 notice. It allows for an early end to the tenancy. It says: "50 (1) If a landlord gives a tenant notice to end a periodic tenancy under section 49 [landlord's use of property], the tenant may end the tenancy early by (a) giving the landlord at least 10 days' written notice to end the tenancy on a date that is earlier than the effective date of the landlord's notice, and (b) paying the landlord, on the date the tenant's notice is given, the proportion of the rent due to the effective date of the tenant's notice, unless subsection (2) applies. (2) If the tenant paid rent before giving a notice under subsection (1), on receiving the tenant's notice, the landlord must refund any rent paid for a period after the effective date of the tenant's notice. (3) A notice under this section does not affect the tenant's right to compensation under section 51 [tenant's compensation: section 49 notice]."

なのでtenancy actのもと、　返金する義務があります。

ソース
http://www.housing.gov.bc.ca/rtb/bc_laws/RTA.html#section49

住む州によっては引っ越し代も出してもらえるので、よく調べてください。