The sentence is agrammatical if only because the adjective sa cannot end a sentence.

Without more clues, it might be a seriously misspelled, phonetic transcription of :

Toujours elle écoute ça. (a colloquial way to say: elle écoute toujours ça)

but I really doubt someone would really use à l’ for elle.

Alternatively, a word might be missing for:

Toujours à l’écoute de ça. (always listening/attentive to it)

After knowing the context, the author is a Réunion island native. This clearly explains both the Réunion créole spelling of sa for the French ça and the lack of de.

A quick search of her comments on You Tube and other sites shows she sometimes writes in Créole réunionnais and uses sa for ça:

Larissa Grondin il y a 2 ans
vient dans mon braaas rienk aou y gagne réconfort amoin. .. ♥

Toujours ô top ti son la hun . big up
Larissa Grondin Il y a 3 ans

Larissa Grondin il y a 3 ans
c’est sa le bon son ♡ ! .

One should manage their expectations when reading comments or chats on French-speaking social networks: they are often written in relaxed French where spelling, grammar and punctuation rules are seen as unimportant, and are often meant to transpose how the writer would spontaneously speak in colloquial French.

In this case, my take is that the writer wanted to say:

[C’est une chanson dont je suis] toujours à l’écoute, ça !

The confusion in spelling of ça/sa is a typical grammar mistake among young French native speakers when they learn to write (from my own school memories, native speakers typically learn in grammar lessons about that around the age of 8/9). It is yet quite common among “uneducated” (no prejudice intended, I cannot find a better word…) native speakers, and is even frequent in “short messaging” language, because it is faster to type than ça or even ca on a French phone keyboard (you can find other instances such as eg. “ses” used for “c’est”).