We often use the phrase "very unique". But "unique" really means "the only one", so it should not be qualified. Delete the word "most" or change the description to something that can be modified, like "innovative".
2. Pronoun reference:
As a rule, the pronoun should refer to a previous noun. In this case, unless we assume the referent was established in an earlier sentence, we don't know what "it" is. To avoid confusion, it might be better to say something like "...the skaters' program was...".
If we decide to keep the word "its" in the sentence, we need to keep in mind that it's a contraction of "it is" and that we therefore need an apostrophe to indicate that a letter has been omitted.
4. Passive voice:
The verb form depends on how we construe the subject. If we go with something like "...the skaters' program", we can use the simple past: "...the skaters' program was the most innovative...". Otherwise, we might use the past participle: "...it was the most innovative program skated..."
5. Pronoun reference:
Again, unless we assume the referent was established in an earlier sentence, we don't know who "they" are. It might be better here to make this clear by saying something like "the pair" or "the skaters".
6. Word form:
"Unbelievable" is an adjective, but we want to modify a verb ("are skating"), so we need an adverb ("unbelievably"). Otherwise, we need to change the verb into a noun and say something like "...their skating was unbelievable..."
7. Verb tense/form:
The action happened over a very short period of time, so it might be better to use the simple past tense ("wasn't") instead of the present perfect ("hasn't been"), and follow it with the present participle ("surprising") instead of the past participle ("surprised").
8. Verb tense:
Again, use the simple past ("gave") instead of the present perfect ("have given").
9. Article use:
“The” refers to something definite, but in this case "standing ovation" is indefinite (there could have been any number of standing ovations during the competition), so we need to use the indefinite article ("a").
We could use direct speech here (putting the comments in quotation marks), but we often report speech indirectly. In that case it might be helpful to put "that" after the reporting verb ("...said that... and that..."). Also, remember to put a comma before the dependent (after "competition").
The commentator said that the skaters' program was the most innovative one at the competition and that their skating was unbelievable; therefore, it was no surprise that the audience gave them a standing ovation.